Wire Sizing

What Size Wire for 30 Amp 200 Feet Away

Pre-calculated NEC-compliant wire size for 30 amps at 200 feet on a 240V single-phase circuit. Immediate answer below.

Recommended Wire Size

Copper
6 AWG
Voltage drop: 2.46% (5.89V)
Voltage at load: 234.1V
Controlling factor: Voltage Drop (3% limit)
Aluminum
4 AWG
Voltage drop: 2.54% (6.1V)
Voltage at load: 233.9V
Controlling factor: Voltage Drop (3% limit)

Based on NEC Table 310.16 (75°C column), single-phase, 240V, 3% max voltage drop, one-way distance 200 ft.

Wire Comparison Table

Wire SizeAmpacityV-Drop (V)V-Drop (%)V at LoadStatus
14 AWG15A37.68V15.7%202.3V
12 AWG20A23.76V9.9%216.2V
10 AWG30A14.88V6.2%225.1V
8 AWG50A9.34V3.89%230.7V
6 AWGREC65A5.89V2.46%234.1V
4 AWG85A3.7V1.54%236.3V
3 AWG100A2.94V1.23%237.1V
2 AWG115A2.33V0.97%237.7V
1 AWG130A1.85V0.77%238.2V
1/0 AWG150A1.46V0.61%238.5V
2/0 AWG175A1.16V0.48%238.8V
3/0 AWG200A0.92V0.38%239.1V
4/0 AWG230A0.73V0.3%239.3V
250 kcmil255A0.62V0.26%239.4V
300 kcmil285A0.51V0.21%239.5V
350 kcmil310A0.44V0.18%239.6V
400 kcmil335A0.39V0.16%239.6V
500 kcmil380A0.31V0.13%239.7V

Table shows all standard AWG/kcmil sizes for 30A at 200 ft on 240V (copper). Green check = meets both ampacity and 3% voltage drop. REC = smallest compliant size.

Key Considerations

For a 30A circuit at 200 feet on 240V, both ampacity and voltage drop must be satisfied. NEC recommends keeping the total voltage drop (feeder + branch) under 5%, with no more than 3% on either segment alone.

Copper conductors at 75°C column (THHN/THWN-2) are assumed. If using 60°C terminations, derate the ampacity to the 60°C column values. Verify the temperature rating of your terminals.

For runs exceeding 200 feet, conduit fill becomes important. Verify that the selected wire size fits within the maximum fill allowance of your conduit per NEC Chapter 9, Table 1. Consider upsizing the conduit rather than downsizing the conductor.

Frequently Asked Questions

What size wire do I need for a 30 amp service at 200 feet?
For a 30A/240V circuit at 200 feet, use 6 AWG copper (2.46% drop) or 4 AWG aluminum. This keeps voltage drop within the NEC-recommended 3% limit.
Can I use aluminum wire for a 30 amp circuit?
Yes. Aluminum wire is a cost-effective alternative for larger circuits. For 30A at 200 feet, use 4 AWG aluminum (2.54% voltage drop). Aluminum requires AL-rated connectors and anti-oxidant compound at all terminations.
What happens if the voltage drop exceeds 3%?
Voltage drop above 3% reduces equipment efficiency, can cause motors to overheat, and may violate NEC 210.19(A) Informational Note No. 4. For a 30A circuit at 200 feet on 240V, exceeding 3% means the load receives less than 232.8V, which can damage sensitive electronics and shorten appliance lifespan.

Need a Custom Calculation?

Different voltage, three-phase, or custom max drop percentage? Use our interactive calculator.

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